Omegas, having weaker constitutions than other wolves, were more susceptible to sickness, and since the servant population was the largest in the palace grounds, it was a logical place to start.
They also planned to monitor the noble households and the general residents, such as shopkeepers and city dwellers. Fortunately, there were no slums in the werewolf kingdom, especially not in the Capital. Unlike human cities that sometimes suffer from mismanaged economies and extreme poverty, werewolves thrived as a unified race.
They rose and fell as a pack. Even though nobles held status and power, they were still bound by duty to the rest of the pack. The less privileged, particularly the omegas serving noble houses or the Royal Family, were still given proper food, shelter, and care. It was a social order rooted in strength and unity, not division.